1. Field of the Invention
This invention relates to phase stable, liquid nonaqueous detergents, which contain enzymes and oxidants, and have prolonged physical stability, even at elevated temperatures for extended periods of time.
2. Brief Description of the Prior Art
There are many instances of liquid, nonaqueous detergent formulations in the prior art. Maguire et al., U.S. Pat. No. 4,123,395, discloses an automatic dishwater detergent composition comprising a low-foaming nonionic surfactant and a sulfonated aromatic compatibilizing agent having a CMC greater than 1% by weight at 25.degree. C., in which the nonionic:sulfonated compatibilizing agent ratio is 2:5 to about 5:3, and the composition is a paste, a gel or a nonaqueous liquid. The compositions of Maguire would be inappropriate for use as a laundry detergent. Automatic dishwaters generally wash dishes at much higher temperatures than washing machines launder clothing, and the type of foaming surfactants utilized in laundry detergents would be inappropriate for use in ADWD's. Further, Maguire does not teach, disclose or suggest the need to provide phase stable, substantially nonaqueous liquid detergents.
van Dijk, U.S. Pat. No. 3,630,929, discloses a substantially nonaqueous liquid detergent consisting essentially of nonionic surfactant, detergent builder, an inorganic carrier, and an acid solubilizer. This reference discloses the need to use an inorganic carrier to prevent phase separation. However, the use of such inorganic materials apparently has deleterious effects on solubility of the composition, since an acid solubilizer, such as acetic acid must also be present.
Carleton et al., U.S. Pat. No. 4,264,466, discloses a liquid detergent mull comprising a dispersed solid in a liquid nonionic surfactant, which is stabilized by a chain structure clay. This particular formulation suggests that a "chain structure type" clay must be present as a suspending material. Applicants however, have found that chain structure type clays adversely affect solubility of liquid detergent formulations. Moreover, chain structure clays have also been found to cause deleterious results in solubility and pourability upon storage, and also upon the addition of extraneous water, in substantially nonaqueous liquid detergents.
Hancock et al., U.S. Pat. No. 4,316,812, discloses a liquid, nonaqueous detergent comprising a dispersion of solids in a liquid nonionic surfactant having a pour point of less than 10.degree. C., in which the solids comprise builders and an oxygen bleach, and there is allegedly no dispersant for the solids. However, Hancock apparently does require a dispersant which is either a finely divided silica (Aerosil), a polyethylene glycol, or both (Cf. Examples 1, 2 and 5 of Hancock).
However, the art does not disclose, teach or suggest that lower alkylated, sulfonated, fused ring arylenes can dramatically and unexpectedly improve physical stability of liquid, nonaqueous detergents. Moreover, none of the art discloses, teaches or suggests that a phase stabilizer which is a lower alkylated, sulfonated, fused ring arylene has dramatic and unexpected physical stabilizing properties in substantially nonaqueous liquid detergents.